title: Prognostic value of dual-time-point 18F-fluorodeoxyglucose positron emission tomography in patients with pulmonary sarcoidosis.
abstract: OBJECTIVE
  The value of dual-time- point (18) F-FDG PET was investigated to predict the prognosis of patients with pulmonary sarcoidosis.
  
  
  METHODS
  Twenty-one patients with pulmonary sarcoidosis underwent (18) F-FDG PET examinations at two time points: an early scan at 60min and a delayed scan at 180min after injection of (18) F-FDG. Standardized uptake values (SUVs) at the two time points and the retention index (RI-SUV) calculated from these were evaluated. To evaluate disease progression, all patients underwent chest CT 1year after (18) F-FDG PET. Using these results, the accuracy of (18) F-FDG PET parameters and (67) Ga uptake for predicting disease persistence were compared, and the correlations between those parameters and serum markers were assessed.
  
  
  RESULTS
  RI-SUV was significantly higher in patients with increased or unchanged pulmonary lesions at follow-up CT (persistent group; 21.3±9.6%) than in patients with improved pulmonary lesions (improved group; -9.2±28.6%, P=0.0075). The diagnostic accuracy of RI-SUV in the persistent group was significantly greater than that of early SUV or (67) Ga uptake, and serum soluble IL-2 receptor showed a significant correlation with RI-SUV.
  
  
  CONCLUSIONS
  RI-SUV showed better diagnostic accuracy compared with early SUV or (67) Ga uptake, in patients with persistent lung involvement at 1year. It may be a useful measure of persistent inflammation in patients with pulmonary sarcoidosis.
authors.affiliation: Departments of Respiratory MedicineRadiologyBiomedical Imaging Research Center, University of Fukui, Fukui, Japan. umeda@u-fukui.ac.jp
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Umeda
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Demura
authors.forename: Miwa
authors.initials: M
authors.lastname: Morikawa
authors.forename: Shingo
authors.initials: S
authors.lastname: Ameshima
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Tsuchida
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Fujibayashi
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Okazawa
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ishizaki
mesh_terms: D000328:Adult; D005260:Female; D019788:Fluorodeoxyglucose F18; D005710:Gallium Radioisotopes; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D011237:Predictive Value of Tests; D011379:Prognosis; D013902:Radiography, Thoracic / Q000379:methods; D015375:Receptors, Interleukin-2 / Q000097:blood; D017565:Sarcoidosis, Pulmonary / Q000175:diagnosis*; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D005710:Gallium Radioisotopes; D015375:Receptors, Interleukin-2; D019788:Fluorodeoxyglucose F18